Enable buttons appear to do nothing.

I can't tell when any of the channel plugins in the properties are enabled or not. None of the "Enable <streamtype> Channel> buttons change when I click them. There is the highlight border when I click one, but the button text doesn't change to "Disable <streamtype> Channel" or similar behaviour as I would expect. As a result, I can't tell from the properties page what state any of the plugins might be currently toggled to.